A typical formula for a dried coffee whitener is
______________________________________ Hydrogenated vegetable fat or oil 35% Protein (e.g. sodium caseinate) 5.25% Buffering agent (e.g. K.sub.2 HPO.sub.4) 2% Emulsifier, (e.g. mono- diglyceride) 2.5% Carbohydrate, (e.g. 24 D.E. corn 55.25% syrup solids) ______________________________________
A good dry coffee whitener formulation is one which, on reconstitution in coffee, forms a stable emulsion wherein the particle size of the fat or oil in the emulsion is about 1--3 microns in diameter. This provides a whitening effect, produced primarily as a result of light reflected from the surface of the finely emulsified fat globules. The carbohydrate acts as a carrier for the fat to retard coalescence of the fat and provides some sweetness effect. Emulsifiers such as mono- and diglycerides, diacetyl tartaric acid esters of mono- and diglycerides, propylene glycol monostearate, lecithin, and the like, have in the past been incorporated in the formulation to maintain the fat globules in dispersion. The protein, such as sodium caseinate, or soybean protein, has been found to be necessary to stabilize the emulsion through the drying step so that when the dried product is reconstituted in coffee, a stable emulsion is provided. The protein encapsulates the oil or fat droplets and binds water, thus preventing separation of the fat and coalescence of the droplets to form fat globules on the surface of the hot coffee. Normally, the protein is present in an amount of about 5% to 10%.
In formulations which contain protein, it is also common to include in the product stabilizing salts such as sodium citrate, tetrasodium pyrophosphates, etc., to improve the colloidal dispersibility of the protein and prevent what is termed "protein feathering" or precipitation of the protein due to acidity of the drink to which the whitener is added.
The protein usually employed in dried coffee whiteners is sodium caseinate. However, casein is milk derived and becoming scarce and expensive. Moreover, while sodium caseinate is legally defined to be a non-dairy material, its inclusion may make the product unacceptable to some ethnic groups.
There have been several attempts to replace sodium caseinate with other water dispersible proteins such as soy protein, but these have all been less than satisfactory. This is due to off-flavors, feathering of the protein in coffee, fat separation, poor whitening properties, and other problems. In fact, experience with other proteins, or with reduced amounts of caseinate in dried whiteners, has consistently been so unsatisfactory that any success in this respect can be deemed to be nothing short of surprising.
In prior U.S. Pat. No. 4,045,589, to Petrowski et al, it is proposed to eliminate the protein in a dried fat emulsion product by incorporating in the formulation a chemically modified dextrinized starch having a lipophilic character. The patent reports that such chemically modified starches were found to be effective in maintaining a stable emulsion subsequent to drying the liquid emulsion concentrate, eliminating the need for protein. Specifically, the patent proposed a formulation comprising vegetable fat or oil, carbohydrate, emulsifier, and the chemically modified dextrinized starch having a lipophilic character. The emulsion concentrate prior to drying had a pH below about 4.0.
A similar disclosure is contained in prior U.S. Pat. No. 3,563,761, which teaches the use of lactalbumin phosphate as a replacement for sodium caseinate.
In prior U.S. Pat. No. 4,025,659 to Cho et al, the problem of soy protein isolate feathering is said to be overcome by maintaining a predetermined ratio of caseinate to soy protein isolate, the combined proteinaceous content from the soy protein and caseinate being about 10% by weight based on the dry weight of the coffee whitener formulation. Specifically, the formulation contains sugar, fat, stabilizing salt, emulsifier, and proteinaceous ingredient, the casein providing at least about 0.9% by weight (dry basis) of the whitener composition.
U.S. Pat. No. 3,958,033 to Sims et al describes a protein-free clear fluid emulsion concentrate said to be shelf stable and useful as a coffee whitener. Critical ingredients, for instance in Example 4 of the patent, were sucrose (46.6%), fat (25%), water (23.4%), and sodium stearoyl-2-lactylate (5%). An adjunct emulsifier, for instance propylene glycol monostearate, may also be present. The disclosure of this patent is limited to liquid coffee whiteners. It is believed that the stability of the emulsion is primarily attributable to the large amount of sugar employed and viscosity of the emulsion by virtue of the sugar. A consumer could well find the sweetness level of the coffee whitener to be objectionable. Further, the amount of sodium stearoyl-2-lactylate required is well above the legal limit* permitted for this ingredient in coffee whiteners. Finally, dried and liquid coffee whiteners are very different in character and the experience obtained with one generally is not transferable to the other. FNT *Established at 0.3% basis total formulation, wet or dry, by the Food & Drug Administration, 21 Code of Federal Registry, part 172.846 (3)
Copending application Ser. No. 254,467, assigned to assignees of the present application, describes a non-dairy fluid coffee whitener adapted to be added to an acidic, hot environment, prepared by pasteurizing and homogenizing a water-rich lipoidal emulsion consisting essentially of about 6-15% edible fat, about 0.6-1.5% lipoidal emulsifier, and water, the emulsifier comprising about 0.3-1.05% of a low HLB mono- and diglyceride component or a propylene glycol ester and about 0.1-0.45% hard, ionizable lipoidal emulsifier component selected from the group consisting of sodium or calcium lactylated esters of fatty acids and sodium stearyl fumarate, the coffee whitener being protein free.